The embodiments of present invention relate to a fabricating method of an array substrate, an array substrate and a display device.
With the maturity of the photoelectric display technique, the panel display apparatus has found increasingly wider applications. Thin Film Transistor Liquid Crystal Display (TFT-LCD) has become the main research trend for the display device products so as to gradually replace the traditional ray tube display device in recent years, due to its characteristics such as longer service time, higher photo-efficiency, lower radiation and lower power consumption.
The TFT-LCD is formed with an array substrate and a color filter substrate by a cell-assembly process. A liquid crystal is injected between the array substrate and the color filter substrate. Generally, the array substrate comprises a substrate, and a gate metal film, a gate insulating film, a semiconductor film, a source-drain metal film and a transparent conductive film provided on the substrate. To ensure insulation among structural units in the array substrate, it's usually required to arrange insulating layers between the gate metal film and the transparent conductive film, and between the source-drain metal film and the transparent conductive film. The gate metal film is used to form a gate electrode and a gate line, the source-drain metal film is used to form a source electrode, a drain electrode and a data line, and the transparent conductive film is used to form a common electrode or a pixel electrode etc.
Conventionally, the drain electrode is usually connected to the pixel electrode through a via hole. Furthermore, it is also necessary to provide the array substrate with a gate line through hole and a data line through hole. It's necessary for the gate line through hole to pass through several layers above the gate metal film and reach the gate metal film, so as to achieve the connection between the gate line and an external signal input apparatus, and thus providing electrical signals to the gate line; whereas the data line through hole passes through several layers above the source-drain metal film and reaches the source-drain metal film, so as to achieve the connection between the data line and the external signal input apparatus and thus providing electrical signals to the data line.
In an example of a conventional array substrate operated in a fringe field switching mode using the Advanced Super Dimension Switch (ADS) technology, the fabricating method of the array substrate requires five patterning processes as following: forming a first transparent conductive film comprising a plate electrode pattern in a first patterning process, forming the gate metal film comprising a pattern of the gate electrode and the gate line in a second patterning process, forming the semiconductor film comprising a pattern of the source electrode, the drain electrode, the data line, the semiconductor silicon islands in the third patterning process, forming an insulating layer comprising the via hole for the electrical connection between the drain electrode and the slit electrode, the gate line through hole and the data line through hole in a fourth patterning process, and finally forming the second transparent conductive film comprising the slit electrode in a fifth patterning process.
It is found that a conventional fabricating method of the array substrate has at least the following problems such as long production cycle, high fabrication cost and low yield due to numerous patterning processes.